Moneyline odds, also known as American odds are probably the most foreign odds format to those of us outside of North America. And at first they appear a little confusing. But it is helpful especially when listening to Americans speaking about gambling odds in sports broadcasts or podcasts. So, let’s see how we can convert Moneyline odds into their respective implied probabilities.
There are two instances of Moneyline odds.
The first are ‘minus’ moneylines. This is expressed as for example 120. But what does this mean exactly?
Well, it is essentially saying that to win 100 you have to make a bet of 120. In other words, if you place 120 on that outcome, you will receive a profit of 100.
The other instance are ‘plus’ moneylines. This is expressed as for example +180.
This means that if you bet 100, you will win 180.
So how do we convert the ‘plus’ and the ‘minus’ moneyline odds into their implied probabilities?
For ‘minus’ moneyline odds, it’s the following calculation.
( – (minus moneyline odds)) 

( – (minus moneyline odds)) + 100) 
So let’s take our example of a moneyline odds offer of 120.
Implied probability 
= 
( (120) / (( (120)) + 100) 
Implied probability 
= 
120 / (120 + 100) 
Implied probability 
= 
120 / 220 
Implied probability 
= 
0.545 
Multiplied then by 100, we get the implied probability percentage of 54.5%.
Now the calculation for ‘plus’ moneyline odds, we make the following calculation:
100 divided by (plus moneyline odds + 100)
So let’s use our example of moneyline odds offer of +180
Implied probability 
= 
100 / (180 + 100) 
Implied probability 
= 
100 / 280 
Implied probability 
= 
0.357 
Multiplied then by 100, we get the implied probability percentage of 35.7%.